The Senate voted 69-27 in favor of the Internet sales tax bill (also known as the Marketplace Fairness Act) on Monday. The Marketplace Fairness Act would allow states to force out-of-state retailers to collect sales tax on Internet purchases -- even if the e-tailer has no physical presence in that buyer's state.

The legislation offers an exemption for merchants that generate less than $1 million in annual out-of-state revenue.

However, many e-tailers like eBay and Overstock.com oppose the new bill, saying that it would hurt small businesses.

Those who are onboard with the legislation include Amazon, which is looking to simplify its U.S. state sales tax payments, and brick-and-mortar stores like Wal-Mart and Best Buy, which have complained about the unfair advantage online retailers have when it comes to the lack of sales tax collection in certain states.

Also, state government's in need of extra revenue like the idea of the new bill. The California Board of Equalization, for instance, said it made $96.4 million in sales tax on internet commerce from September-December 2012, which is the first full quarter that the state started collecting.

Back in April, the Marketplace Fairness Act scored a big victory in a procedural vote of 74-20 in the Senate. It even won backing from U.S. President Barack Obama.

While the Marketplace Fairness Act has had an easy time in the Senate, things are expected to change in the House of Representatives. The issue is that Republicans control the House, and they refuse to consider new federal revenue from eliminating tax breaks (which would be part of tax reform).

House Speaker John Boehner now plans to deliver the bill to the House Judiciary Committee.

It's not that simple. They have to keep track of how to tax by both where the customer is ordering from as well as where the company is shipping from and how they're getting it to the customer.

Many small businesses don't work from stock. They have a middle man who will sometimes ship to the warehouse/business who then ships it as sometimes drop ships directly to the customer.

So, if the small business is based in Montana, who doesn't require collecting tax, and a customer from Colorado orders something from stock and something that has to be drop shipped from California, they don't collect the tax on what was shipped from stock while they have to both collect tax for what is dropped shipped as well as pay tax themselves on what was drop shipped. (Technically, a drop ship is selling from middle man to business and then from business to customer, but only shipped once. So, twice the tax.)

The software will have to handle all that automatically. That's some complex stuff.

In addition, there may be complications of a business of all digital goods that operates from one state and has their servers hosted in another state. There's also a lot of talk by state government about flat taxes rather than % rate taxes on digital downloads. On top of all that, the states all handle their laws individually, and there will be changes from one state or another all the time, so we're talking monthly updates to the program, or perhaps even more often than that.

How do you code web sites around all that? A business owner would have to deal with updates not just in the program on the tax rates, but also the checkout process if some new circumstance comes up.

In the first place, taxes must be charged for localities, not just states. This means the counties/cities/etc where the item is delivered. And, as you may know, the city listed in the mailing address often has little to do with the city the location actually belongs to. This is, indeed, a very complex problem.

On the other hand, each participating state is required to provide, free-of-charge, software which performs all of these calculations. Further, they are required to either provide 90 day notice of any changes to the rules, or forgive any errors for 90 days after the change.

A bigger problem is that these entities often charge different tax levels for different items. For example, here in Ohio, food is not taxed at all. So now, sellers must categorize each item they are selling. This might seem simple at first, but keep in mind the categories must match each and every state's laws, a much more daunting task. (and also difficult to automate.)